Boiler



V. W. HOXlE Oct. 18, 1932.

BOILER Filed Jan. 26, 1929 2 Sheets-Sheet l 5 I it I INVENTOR ATTOTRNEYG dicates a furnace that may be heated Patented Oct. 18, 1932 UNITED STATES PATENT OFFICE VIVIAN W. I-IOXIE,

OF SAN FRANCISCO, CALIFORNIA, ASSIGNOR TO THE BABCOGK & WILCOX COMPANY, OF BAYONNE, NEW JERSEY, A

CORPORATION OF NEW JERSEY BOILER Application filed January 26, 1929. Serial No. 335,309.

This invention relates to a boiler comprising two units one located above the other, one of the units comprising inclined tubes connected to headers and the other comprisinclined tubes connected to horizontally disposed drums, the two units being connected by nipples so as to work together as a single boiler. The invention will be understood from the description in connection with the accompanying drawings, in which Fig. 1 is a vertical section through an illustrated embodiment of the invention, and Fig. 2 is a section along the line 22 of Fig. 1

In the drawings reference character 1 inby burners 2 or in any other convenient manner. A bank of inclined tubes 3 spaced sufficient distances apart to decrease troubles from slagging, is located above the furnace 1 and the ends thereof are connected to uptake headuptake headers 4 some distances into a ers 4 and downtake headers 5. The lower ends of the downtake headers 5 are connected by nipples to a cross mud drum 5. Nipples 6 extend from the upper ends of the horizontal drum 7. A feed intake pipe 8 is connected to the drum 7. A bank of tubes 9 inclined in a direction opposite the inclination of the tubes 3 connects the drum 7 to a horizontally disposed steam and water drum 10. A curved baffle 11 is located inside of the drum above the ends of the tubes 9 and a curved baffle 12 is located inside of the drum 7 above the ends of some of the tubes 9 and below the ends of some of the other tubes 9.

Long nipples 13 extend from the water space of the steam and water drum 10 to the upper ends of the downtake headers 5. A pipe 15 extends from the steam space of the steam and water drum 10 to the inlet header 16 of the superheater. The inlet header 16 of the superheater is'connected by rows of V-shaped tubes 17 to the outlet header 18. The superheater is located in the V-shaped space between the banks 3 and 9 of tubes. A pipe 19 leads from the outlet header 18 to the steam main.

A baffle 20 extends along the upper side of the lowermostrow of tubes 9 from the drum 7 for some distance and abafile 21 extends from the end of the bafile 20 across about half of the tubes 9. i A baffie 22 extends from the inner edge of the outlet 23 for waste gases across slightly more'than half of the tubes 9. Safety valve nozzles 24l may be pro vided in the steam and water drum 10 in the well-known manner.

The hot products of combustion from the furnace 1 pass in a single pass across tubes 3 and as thesetubes are spaced far apart the danger of slagging is minimized. The hot gases then pass across the tubes 17 of the superheater and thence a plurality of times across the tubes 9, asindicated by the ar rows, and finally out through the outlet 23. With the superheater installed in the space, as illustrated and described, it is veryeasy to get at the same for inspection, and ample space is provided for repair ,or cleaning. The

tube spacing ofthe tubes 9 may be closer than that of the tubes 3, as there is no danger of excessive slagging of these tubes and there is an advantage in abstracting heat from the partly cooled gases.

The water level is maintained at about the middle of the upper drum 10, so that in addition to the circulation from this drum downwardly through the nipples 13, tubes 3 and headers 4 to the drum 7, back to the drum 10,-there is also some circulation from the drum 10 through the lower middle tubes 9 to the drum v7 and thence through the upper tubes 9 to the drum 10, and also through lower tubes 9 from drum 7 to drum 10.

The steam and water from the lower bank 3 of straight tubes heatedby thehotter gases pass into the lower drum 7 of the upper bank 9 and then through the tubes of the upper bank especially the higher ones, into the steam and water drum 10 where separation occurs. This results in a more vigorous motion of the tube contents of the tubes of the upper bank 9 than would result from the steam made in these tubes acting alone.

It is to be understood that sinuous headers may be used or the headers may be made of cylindrical or drum shape, if desired, or rectangularly shaped boxes with stays may be used.

The feed water entering the drum 7 appears to pass circumferentially along the bottom of this drum and in between the nipples 6, then into the lower rows of tubes 9, with the result that the air coming in with the feed water separates out as follows:

The entrained air separates in the drum 7 to the upper portion and passes up with the water and steam through the top tubes of bank 9 into the drum 10. The dissolved air coming in with the feed water is liberated as the new feed water is passing through the lower rows of tube bank 9 and into the drum 10. The air from both sources passes out through the dry pipe in the drum 10. v The water entering the downtake nipples 13 is water from which air and entrained foreign matter has been to a great extent removed or separated. This water has passed over heating surface which has not been subjected to maximum temperatures. This ac tion decreases or does away with any danger of air or scale forming ingredients entering the lower rows of straight tubes in tube bank 3, t ius'reducing tube losses and permitting higher evaporative rates without danger to these tubes. The water before entering the tube bank 3 may be said to be purified or cleansed. Higher rates of evaporation is possible with this condition.

Due to the fact that the water has, soon after entering the boiler, passed over the heating surfaces the tube bank 9 the initial tendency to deposit scale is greatest in these tubes and in this zone in the tube bank 9 the temperature of the products of combustion have been so reduced that the ordinary danger of burning tubes from scale incrustation is removed.

The temperature differential between the mixture of all the water entering the steam drum 10 and the steam in this drum corresponding to the working pressure will be very slight, if any. The result is an efficient liberation of steam in the drum 10 also increasing the tendency to obtain dry steam.

The initial contact of entering feed water is made with the heating surface where the temperature of the gases of combustionis coolest.

I claim:

1. In a steam boiler, tubes connected to headers, a bank of tubes inclined in the opposite direction and located above the first bank, drums at opposite ends of said last named bank of tubes, connections between said tubes, and means to cause hot gases to pass across the upper ends of the tubes of the second bank and then across the lower ends thereof.

2. In a steam boiler, a bank of inclined tubes connected to headers, a bank of tubes inclined in the opposite direction and located above the first bank, drums at opposite ends of said last named bank of tubes, connections a bank of inclined insane? between said tubes, and means to cause hot gases to pass across the first bank of tubes and subsequently across the upper ends of the tubes of the second bank and then across the lower ends thereof.

3. In a steam boiler, an uptake header a downtake header, a bank of horizontally inclined straight tubes connecting the headers, a second bank of tubes inclined oppositely to the tubes of the first bank and located above the first bank, a lower transverse drum above the uptake header and at the lower ends of the tubes of the second bank, a steam and water drum located at an elevation above that of the first drum and having the upper ends of the tubes of the second bank connected thereto, tubes directly connecting the uptake header and the first drum, direct connections between the downtake header and the steam and water drum, and means to cause furnace gases to pass across the upper ends of the tubes of the .second bank and then across the lower ends thereof.

4. In a water tube steam boiler, an uptake header, a downtake header, a bank of horizontally inclined straight tubes directly connecting said headers, a first drum directly connected to the upper portion of the uptake eader to receive the fluid mixture discharged therefrom, a steam and water drum at an elevation higher than that of the first mentioned drum, a bank of tubes inclined oppositely to the inclination of the tubes of the first bank and directly connecting the drums to afford mixture recirculation between said drums, downtake connections between the steam and water drum and the downtake header, and means to cause furnace gases to pass across the upper ends of the tubes of the second bank and subsequently across their lower ends, the first bank of tubes with their connected headers constituting a single gas pass through which furnace gases pass to the upper ends of the tubes of the second bank.

5. In a water tube steam boiler, boiler tube headers, a lower bank of inclined tubes directly connecting said headers, a water chamber directly connected to the upper portion of one of said headers to receive the mixture discharged therefrom and from said tubes, a steam and water chamber located at an elevation higher than that of the first chamber, an upper bank of tubes inclined oppositely t0 the inclination of the first mentioned tubes and directly connecting said chambers, means connecting said last mentioned chamber to the remaining header for the first bank of tubes, means directing the furnace gases across the tubes of the first bank for their full length in a single gas pass, and means to subsequently direct the furnace gases across the upper ends of the tubes of the second bank and subsequently across the lower ends of the tubes of the second bank.

6. In a water tube steam boiler, a boiler setting, a steam and water drum, a second drum located in the setting at an elevation beneath that of the first drum, a bank of inclined tubes directly connecting said drums to afford mixture recirculation between said drums and to constitute with said drums a boiler section of the drum type, a steam superheater having headers at the side of the setting adjacent the steam and water drum and located beneath said bank of tubes, a furnace beneath said superheater and said bank of tubes, a natural circulation boiler section of the sectional header type interposed between the superheater and the furnace so that all of the furnace gases pass across said section in a single gas pass to the superheater, means to cause the furnace gases to pass from the superheater across the upper ends of the tubes of the first bank and subsequently across the lower ends of those tubes, means affording direct mixture flow from the steam and water drum to the intake end of said natural circulation section and means affording direct discharge from the outlet end of the natural circulation section to the second drum, the natural circulation boiler section ving tubes with a coarse or wide spacing so as to prevent undesirable draft loss by excessive slagging.

7. In a water tube steam upper and lower banks of steam generating tubes, upper and lower gas and liquid separation chambers directly connected by the upper bank of tubes to provide fluid recirculation between the chambers, means directing the discharge from the lower bank of tubes into the lower one of the chambers, means directing fluid from the other chamber to the inlet end of the lower bank of tubes, means for delivering feed water to the lower chamber, means for directing furnace gases across the ends of the upper bank of tubes after they traverse the lower bank of tubes in a single gas pass, and means for subsequently directing the furnace gases across the opposite ends of the upper tubes.

VIVIAN W. HOXIE.

boiler, a furnace, 

